Arthritis is not a disease of old age. Mine started in my teens. A rheumatologist can diagnose arthritis, if that is what is causing your pain. There are medications that can reduce joint inflammation, and thus the pain associated with it.
Anacyde couldn't have said it any better than what I was going to write! So I will just say "ditto"..LOL...
A Board Certified Rheumatologist is your best bet...
Good luck..